My recommendation: stop being an awkward, anti-social ass.
Look, it's clear that you don't personally buy into the whole "religion" thing. That's fine. But these people are deeply committed to their faith, and are willing to spend big chunks of their time trying to help others in the best way they know how. Any reasonable person would politely open the door, respect what they had to say, accept the pamphlet, and then throw it away later. If it's really becoming a problem for you, then put up a sign saying "No Solicitors"; the next time they come around, remain respectful but be firm about how you'd appreciate no more soliciting. They'll understand. Religious folk aren't the crazies you're making them out to be.
...And really now, opening the door with a machete in hand? Give me a ****ing break.
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http://www.youtube.com/watch?v=SBpfwpOPXNc&NR=1&feature=fvwp
~Pinkie Pie is the best pony~